1. Field of the Invention
This invention relates to a long acting pharmaceutical composition of Tiaramide or its pharmaceutically acceptable salt.
More particularly, this invention relates to a long acting pharmaceutical composition which comprises Tiaramide or its pharmaceutically acceptable salt as an active ingredient and a water-particularly insoluble solid substance which melts with warming or heating.
2. Description of the Prior Art
Tiaramide, i.e. 3-[4-(2-hydroxyethyl-1-piperazinyl)-carbonylmethyl]-5-chloro-2-benzothiazo linone or its pharmaceutically acceptable salt as used as an active ingredient in this invention is widely known as an excellent analgesic, antiallergic and antiinflammatory medicine, among which, Tiaramide hydrochloride is marketted in a form of tablet for oral administration use.
As to Tiaramide or its pharmaceutically acceptable salt, it is understood that said drug is very rapidly absorbed in the body, for example, its serum concentration in human beings comes up to the maximum within about one hour after its oral administration.
However, Tiaramide or its pharmaceutically acceptable salt is excreted so rapidly that more than 90% of Tiaramide is excreted in the urine within about 20 hours after its administration, and accordingly its serum concentration decreases rapidly in a short time after its administration.
Due to the behavior of Tiaramide or its pharmaceutically acceptable salt as explained above, it is necessary for patients to take the drug many times a day for efficient therapy.